JP3980445B2 - Small traveling ship - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small traveling boat such as a personal watercraft (also referred to as a personal watercraft (PWC)) that jets a water flow backward and sails on the water by reaction thereof, and particularly relates to an air bleeding structure of an engine. In this specification, air bleeding refers to a broad concept including gas or air containing mist-like oil or fuel.
[0002]
[Background Art and Problems to be Solved by the Invention]
Small traveling boats, for example, so-called jet propulsion type personal watercrafts, have been widely used in recent years for leisure, sports or rescue. In this small planing boat, the hull is generally propelled by injecting water sucked from a water inlet provided on the bottom of the boat under pressure by a water jet pump and accelerating it. In the case of this jet propulsion type personal watercraft, the steering nozzle disposed behind the injection port of the water jet pump is swung left and right by operating the steering handle left and right to Change the injection direction to the left and right and steer the boat to the right or left.
[0003]
By the way, in such a small planing boat, a multi-cylinder engine has a crankshaft arranged along the longitudinal direction of the hull.
In this engine, an oil tank is provided at the bottom of the crank chamber so as to be one chamber with the crank chamber in the case of the so-called “wet sump type”, while in the case of the so-called “dry sump type”. Is provided as a tank that is partitioned from the crank chamber and is an independent space. In any case, the lubricating oil in the oil tank is appropriately supplied to a necessary part of the engine by a feed pump or the like.
In such an engine, the pressure in the crank chamber fluctuates in a pulsating manner as the piston moves up and down and due to blow-by gas from the combustion chamber side. For this reason, in order to prevent the fluctuation of the pressure from becoming a resistance of the lifting and lowering operation of the piston, it is necessary to make the crank chamber communicate with the atmosphere side to alleviate the fluctuation of the pressure in the crank chamber.
[0004]
Specifically, for example, in the case of the “wet sump type”, the crank chamber is connected to the atmosphere side via a breather pipe, or the cam chamber and the cam chamber of the cylinder head portion are connected via a cam chain tunnel. It is configured to reduce pressure fluctuations in the crank chamber by communicating with the atmosphere side by a breather pipe (used in a broad concept including a breather passage) connected to the cam chamber.
[0005]
Further, in the case of the “dry sump type” engine, as in the case of the “wet sump type”, the engine is communicated from the crank chamber to the atmosphere side through a breather pipe, or through a cam chain tunnel. A breather mechanism is required in which the crank chamber communicates with the cam chamber of the cylinder head portion and communicates with the atmosphere side by a breather pipe (used in a wide concept including a breather passage) connected to the cam chamber. In addition, in the case of a “dry sump type” engine, air (air containing blow-by gas) is mixed in the oil sent from the crank chamber by the scavenge pump. The oil tank is also required to have a breather mechanism that allows air that has flowed into the oil tank to escape to the atmosphere.
[0006]
However, as described above, in the case of a small planing boat in which the longitudinal direction of the oil tank is arranged along the longitudinal direction of the boat (in the direction of the crankshaft of the engine), when the boat starts and stops, there is oil due to inertia. The oil in the tank moves to the front or rear and is unevenly distributed in the oil tank, and the base end portion of the breather pipe or the breather hole portion of the breather mechanism may be blocked with oil. When the breather hole portion is closed in this way, the air in the oil tank, which is generated by the lifting operation of the piston or blow-by gas, is temporarily compressed, so that the oil flows out together with the pressurized air. May occur.
[0007]
In addition to when the boat is accelerating and decelerating, depending on the state of the oil in the oil tank, the breather pipe or breather hole is temporarily blocked, and the air in the oil tank is temporarily compressed, A situation may occur where oil flows out to the outside together with the pressurized air.
[0008]
As such a countermeasure, it is conceivable to make the breather pipe or the breather hole very large so as not to block the ventilation cross-sectional area. However, as a matter of fact, such a ventilation cross-sectional area is required to be about 10 to 15 times the ventilation cross-sectional area of a normal breather pipe, etc., but a breather pipe or a breather hole having such a large ventilation cross-sectional area is provided near the engine. In the case of a small planing boat that does not have enough space, it is difficult to achieve the above.
[0009]
The present invention has been made in view of such a situation, and even when the small traveling ship is accelerated or decelerated, the oil in the oil tank moves back and forth to close the air vent hole or the like. Another object of the present invention is to provide a small traveling ship in which only the air in the oil tank can be smoothly released to the atmosphere side even when the air vent hole is temporarily blocked.
[0010]
[Means for Solving the Problems]
The above problem can be solved by a small traveling ship having the following configuration. That is,
In order to achieve the above object, a small traveling ship according to the present invention is equipped with a multi-cylinder engine so that the axial direction of the crankshaft coincides with the longitudinal direction of the hull, and the longitudinal direction in the axial direction of the crankshaft. Is a small traveling ship with oil tanks arranged to match,
Forming the first and second communication ports at at least two positions spaced apart in the front-rear direction of the oil tank;
A chamber having third and fourth communication ports at two spaced apart positions and a fifth communication port communicating with at least one outside air at another position is provided, and the bottom surface of the chamber has a bottom surface of the oil tank. Install it so that it is higher than the oil level inside.
In addition, the first communication port of the oil tank and the third communication port of the chamber are communicated, and the second communication port of the oil tank and the fourth communication port of the chamber are communicated. It is characterized by.
[0011]
Thus, according to the small traveling ship configured as described above, even if the oil in the oil tank moves forward or backward at the time of acceleration or deceleration, the first or second communication port that is either forward or backward is provided. Since the oil is not blocked by the oil, the pressurized air can be released from the communication port not blocked through the fifth communication port of the chamber to the atmosphere side. For example, when the ship accelerates, the oil in the oil tank moves backward due to inertial force. At this time, the communication port on the rear side of the oil tank, for example, the second communication port is closed with oil, Since the front communication port, for example, the first communication port is not blocked with oil, the air in the oil tank can be released from the front communication port to the atmosphere side through the chamber.
Further, when the first and second communication ports are provided apart from each other at the time of acceleration or deceleration, the balance of the degree of blockage by the oil at either of the front and rear ports is the same. In other words, in a state where the degree of blockage is not balanced, air can be released from the communication port having a low level of blockage and escape to the atmosphere via the fifth communication port of the chamber. Then, when the balance of the degree of blockage by the oil at the first and second communication ports is lost in this way and air is released from one of the communication ports, the one side of the communication port is then connected to the chamber side. A one-way circulation path is formed in which air that has been gas-liquid separated in the chamber returns from the other communication port, and smooth air venting is performed.
[0012]
In the small traveling ship, when the third communication port and the fourth communication port are provided at a distance from each other in height, when the hull is sailing in a steady state, Of the two communication ports, the communication port located at the lower position functions exclusively as a communication port for returning the oil flowing into the chamber to the oil tank side. The communication port at a high position functions exclusively as a communication port for releasing air from the oil tank. That is, a one-way oil return circulation system (circulation passage) is formed between the oil tank and the chamber via the communication port, and therefore, a pipe line (pipe) connecting these communication ports is formed. Even if the cross-sectional area is small, an increase in pressure in the oil tank can be effectively prevented.
[0013]
In addition, even in the case where the oil tank is arranged so that the majority of the oil tank is located below the crank chamber of the engine, the air in the oil tank is supplied to the outside of the oil tank. It can escape to the atmosphere without causing it to flow out.
[0014]
Further, in the small traveling ship, most of the oil tank is arranged to be positioned below the crank chamber of the engine, and the oil tank is a separate space separated from the crank chamber. Even in the case of a dry sump engine, the air in the oil tank can be released to the atmosphere without causing the oil to flow out of the oil tank.
[0015]
Furthermore, in the small traveling ship, when the fifth communication port of the chamber is connected to the base end of the breather pipe, the air can escape from the chamber to the atmosphere side through the breather pipe. It becomes.
[0016]
In the small traveling ship, when the tip of the breather pipe is connected to a separator that separates oil and air, the separator can more effectively separate oil and air.
[0017]
In the small traveling ship, the lower end of at least one of the fifth communication port of the chamber, the first communication port of the oil tank, and the second communication port is located within the wall surface around the communication port. If it is configured to protrude in the direction of the air, it is possible to prevent the oil that is about to flow out with the air by the difference in the mass and the viscosity of the oil and the air, based on a concept similar to the so-called “back-to-back” principle. It becomes.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a small boat according to an embodiment of the present invention will be specifically described with reference to the drawings, taking a small planing boat as an example.
[0019]
FIG. 1 is a diagram schematically showing a configuration of an engine and an oil tank portion of a small planing boat which is a small planing boat according to an embodiment of the present invention. FIG. FIG. 3 is a view seen from a direction (side) perpendicular to the crankshaft, FIG. 3 is an enlarged side view showing a part of the structure of the air vent chamber shown in FIG. 2, and FIGS. 4 (a) and 4 (b) are oil tanks. FIG. 5 is an overall side view of the personal watercraft according to the embodiment of the present invention, and FIG. 6 is a plan view of FIG. 5.
[0020]
5 and 6, A is a hull, and this hull A is composed of a hull H and a deck D covering the hull H, and a connecting line connecting the hull H and the deck D all around is a gunnel line G. In this embodiment, the gunnel line G is located above the waterline L of the personal watercraft.
[0021]
As shown in FIG. 6, a substantially rectangular opening 16 is formed on the upper surface of the hull A in a plan view extending in the longitudinal direction, slightly behind the center of the deck D, as shown in FIGS. Thus, a seat S for riding is disposed above the opening 16.
[0022]
The engine E is disposed in a space 20 having a “convex” cross section surrounded by the hull H and the deck D below the seat S.
In this embodiment, the engine E is a multi-cylinder (four cylinders in this embodiment) four-cycle engine E, and the crankshaft 26 is oriented in the longitudinal direction of the hull A as shown in FIG. The output end of the crankshaft 26 is connected to the pump shaft 21S side of the water jet pump P to which the impeller 21 is attached via the propeller shaft 27 so as to be integrally rotatable. Yes. The outer periphery of the impeller 21 is covered with a pump casing 21C, and water taken from a water inlet 17 provided on the bottom surface of the small planing boat is taken in through a water absorption passage 28. It is configured to obtain a propulsive force by being pressurized and accelerated and discharged from the rear end injection port 21K through the pump nozzle (spout part) 21R whose water flow cross-sectional area has become smaller rearward. .
[0023]
In FIG. 5, 21V is a stationary blade for rectifying the water passing through the water jet pump P. 5 and 6, reference numeral 24 denotes a bar-type steering handle. By operating the handle 24 to the left and right, the steering wheel behind the pump nozzle 21 </ b> R is connected via a cable 25 shown by a dashed line in FIG. 6. The nozzle 18 is swung left and right so that the boat can be steered in a desired direction when the water jet pump P is in operation. In FIG. 6, Lt is a throttle lever for operating the rotational speed of the engine E.
[0024]
Further, as shown in FIG. 5, a bowl-shaped reverse deflector 19 is disposed above and behind the steering nozzle 18 so as to be swingable downward around a horizontally disposed swing shaft 19a. The deflector 19 is configured to swing backward to a lower position behind the steering nozzle 18 so that water discharged rearward from the steering nozzle 18 can be turned forward to move backward.
[0025]
In FIGS. 5 and 6, reference numeral 22 denotes a rear deck. The rear deck 22 is provided with an openable hatch cover 29, and a small capacity storage box is formed below the hatch cover 29. 5 or 6, reference numeral 23 denotes a front hatch cover, and a box (not shown) for storing equipment and the like is provided below the hatch cover 23.
[0026]
By the way, in the 4-cylinder engine of the personal watercraft according to the embodiment of the present invention, the longitudinal direction is the same as the direction of the crankshaft 26 below the crank chamber Cr of the engine E as shown in FIG. An oil tank 1 is arranged so as to be. In the case of this embodiment, the oil tank 1 has substantially the same volume as the crank chamber Cr. The oil tank 1 is partitioned from the crank chamber Cr by a partition wall Ps formed of a U-shaped wall formed at the upper end of the oil tank 1 (the portion excluding both ends of the upper end). Another space (space isolated from each other) is formed. In the case of this embodiment, most of the oil tank 1 is located at a position below the engine E. In the case of this embodiment, as shown in FIG. 2, the bottom surface of the oil tank 1 is slanted so that the rear side portion is higher than the front side portion when mounted on the boat. It is configured. In FIG. 2, the left side is illustrated as the front side of the boat (engine), and the right side is illustrated as the rear side of the boat (engine).
In addition, in the oil tank 1, a partition wall (not shown) is provided to partition the oil tank 1 so as to be able to flow back and forth in order to make the oil move back and forth slowly.
As shown in FIG. 1, the oil Oi that has lubricated a necessary portion of the engine E is configured to accumulate at the bottom of the crank chamber Cr. A scavenge pump Sp is disposed at the bottom of the crank chamber Cr, and the oil Oi accumulated at the bottom of the crank chamber Cr is returned to the oil tank 1 by the scavenge pump Sp.
As shown in FIG. 2, the front and rear portions of the oil tank 1, that is, the front and rear portions in the longitudinal direction of the boat, the first and second communication ports in this embodiment, Air vent holes 1A and 1B are formed. Specifically, the air vent hole (first communication port) 1A is provided so as to face in the vertical direction at a position approximately 1/3 from the front end of the upper surface of the front portion of the oil tank 1, and the air vent hole (first 2B) 1B is provided so as to face in the vertical direction at a position approximately 1/3 from the rear end of the upper surface of the rear portion of the oil tank 1.
The air vent holes 1A and 1B are formed so as to protrude downward from the surrounding wall surfaces as shown in an enlarged view in FIG. Instead of the configuration of FIG. 4B, a configuration as illustrated in FIG. 4A may be used. Such a configuration is also adopted in an air vent 2C described later.
[0027]
An air vent chamber 2 is fixed to the upper side of the oil tank 1, in the case of this embodiment, on the side of the cylinder block Cb above the crank chamber Cr by bolting or the like (not shown). As shown in FIG. 2 or FIG. 3, the chamber 2 has a deformed rectangular shape in which the right side portion extends downward, that is, the right side bottom portion 2b is positioned lower than the left side bottom portion 2a. The inside is a single, that is, a space without a partition wall.
In the bottom portion 2b extending downward of the chamber 2, a connection hole 2A, which is a third communication port in this embodiment, is formed so as to face in the vertical direction. It is connected to an air vent hole (first communication port) 1A of the oil tank 1 through a path 3A. Further, in the vicinity of the upper end of the side wall of the chamber 2, another connection hole 2 </ b> B serving as the fourth communication port in this embodiment may be in the vertical direction (or in the diagonally vertical direction as shown in FIG. 1, Alternatively, the connection hole 2B is connected to an air vent hole (second communication port) 1B of the oil tank 1 through a conduit 3B. Yes. The connection hole 2B is provided at a height higher than the connection hole 2A.
In FIG. 1, the pipe line 3B is located behind the chamber 2 and the pipe line 3A. However, in the state shown in FIG.
In addition, an air vent 2C, which is a fifth communication port in this embodiment, is formed in the ceiling wall 2d near the side wall opposite to the connection hole 2B of the chamber 2 so as to face obliquely up and down. The air vent 2C is connected to the cylinder head Ch of the engine E via the first breather pipe Br1 so that the inside of the chamber 2 communicates with the inside of the cylinder head Ch. However, the air vent 2C may be directly connected to the separator 5 via the first breather pipe Br1 as shown by a two-dot chain line in FIG.
As shown in FIG. 1, an air vent connection port 4 is formed at the upper end of the cylinder head Ch, and the air vent connection port 4 is connected via a second breather pipe Br2. Are connected to the separator 5. The separator 5 is connected to the oil tank 1 side by a return pipe 6 as shown by a two-dot chain line in FIG. Further, in the case of the separator 5 of the embodiment shown by the two-dot chain line in FIG. 2, it is similarly connected to the oil tank 1 side by the return pipe 6.
In this embodiment, the air vent holes 1A and 1B are provided at positions above the liquid level Loi in the oil tank 1 when the boat is in a steady state. The air vent hole 1A may be positioned below the liquid level Loi in the oil tank 1 as indicated by a two-dot chain line in FIG.
[0028]
Therefore, according to the present personal watercraft configured as described above, the following effects are obtained. That is,
In this small planing boat, when the engine E is operated, the crank chamber Cr is increased in pressure by blow-by gas from the combustion chamber. These blow-by gas and crank chamber air are mixed in the oil and sent to the oil tank 1 by the scavenge pump Sp.
Then, the air that has entered the oil tank 1 exits from the air vent hole 1A or the air vent hole 1B to the chamber 2 through the pipe line 3A or the pipe line 3B. At this time, the oil in the oil tank 1 may be in a bubbling state due to the vibration of the engine E and the vibration associated with the navigation of the small planing boat. In such a case, the oil in the bubbling state The air enters the chamber 2 through the pipe lines 3A and 3B.
And since the said chamber 2 is large space compared with the pipe lines 3A and 3B, it is decompressed at a stretch here and oil and air isolate | separate. The separated oil moves to the bottom surface of the chamber 2 and returns to the oil tank 1 from the air vent hole 1A through the pipe 3A from the connection hole 2A provided at the bottom.
When the air vent hole 1A is returned to the oil tank 1 in this way, the air vent hole 1A is substantially closed by the oil. Therefore, the air containing the blow-by gas in the oil tank 1 has a low resistance. The air is introduced from the air vent hole 1B into the chamber 2 through the pipe line 3B.
As a result, a one-way circulation path for oil in the oil tank 1, the pipe line 3B, the chamber 2, and the pipe line 3A is formed, and the oil / air separation mechanism starts to work smoothly.
[0029]
When the boat is accelerating or decelerating, it operates as follows. That is, for example, when the small planing boat accelerates, the oil in the oil tank 1 moves backward by inertial force. As a result, the air bleed hole 1B is filled with oil or close to it, and is blocked or almost closed by the oil. In such a case, air is led from the air vent hole 1A provided in the front portion of the oil tank 1 to the chamber 2 through the conduit 3A.
On the other hand, when the small planing boat is decelerated, the oil in the oil tank 1 moves forward by inertial force. As a result, the air vent hole 1A is filled with oil and is blocked by the oil. In such a case, air is led from the air vent hole 1B provided in the rear portion of the oil tank 1 to the chamber 2 through the conduit 3B.
In any of the above states, the space inside the chamber 2 is sufficiently large (volume) to eliminate the “bubbling state” in which the gas and liquid are integrated due to the viscosity of the oil and the pressure of the air. Therefore, the gas and liquid are separated in the chamber 2, the air is discharged from the upper air vent hole 2C, and the oil is supplied to the pipe 3A and / or the pipe 3B. It smoothly returns to the lower oil tank 1 side through the road.
[0030]
4A or 4B, the air vent hole 1A (the air vent hole 1B shown in FIG. 2) and the air vent 2C are inward (downward) from the surrounding wall surface. ), The oil which is trapped by the air which is going to move upward and which flows out to the pipelines 3A, 3B or the first breather pipe Br1 side is blocked.
[0031]
Further, as shown in FIG. 1, in the case of the personal watercraft according to this embodiment, the height of the oil tank 1 can be lowered and disposed in the space below the engine E, so that the narrow engine The room can be used effectively.
[0032]
In the above embodiment, the oil tank is integrally provided below the engine. However, in the case of a dry sump engine, the oil tank is placed at a position other than the engine lower side, for example, the side of the engine or the engine. Needless to say, it may be provided in front of the engine or may be provided separately from the engine.
[0033]
In the above embodiment, the dry sump type engine has been described. However, it goes without saying that the present invention can be similarly applied to a “wet sump type” engine in which the bottom of the crank chamber functions as an oil tank. . In the case of this “wet sump type” engine, the air vent hole is formed on the wall surface such as the wall surface of the upper end portion of the crank chamber.
In the above-described embodiment, the small planing boat has been described, but it goes without saying that the present invention can be applied to other small boats.
In the above embodiment, the air vent port of the air vent chamber is configured to communicate with the cylinder head of the engine via the breather pipe. Instead, the two-dot chain line in FIG. As shown, the breather pipe Br1 may be configured to communicate with the separator 5 directly. Or it can replace with embodiment mentioned above and can also be set as the structure which eliminated the separator.
[0034]
In the above-described embodiment, the chamber 2 is provided above the oil tank 1, but the chamber 2 may be configured such that the bottom surface of the chamber 2 is located above the oil level in the oil tank 1. It ’s enough.
[0035]
【The invention's effect】
According to the small traveling ship of the present invention, even when the oil in the oil tank moves back and forth, such as when the small traveling ship accelerates or decelerates, or in the steady navigation state, the air in the oil tank Only oil is separated from the oil and smoothly released to the atmosphere side, and the oil can be returned to the oil tank side.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an engine as seen from a partially cut crankshaft direction schematically showing a configuration of an engine and an oil tank portion of a small planing boat which is a small personal watercraft according to an embodiment of the present invention. .
2 is a partial cross-sectional view showing the configuration of the engine as viewed from the direction of arrows II-II in FIG. 6, which is a direction (side) perpendicular to the crankshaft of the engine shown in FIG.
3 is an enlarged view showing a part of the structure of the air vent chamber shown in FIG. 2; FIG.
FIGS. 4A and 4B are partially enlarged sectional views showing configurations according to two embodiments of an air vent hole of an oil tank or an air vent port portion of an air vent chamber.
FIG. 5 is an overall side view of a personal watercraft according to an embodiment of the present invention.
FIG. 6 is a plan view of FIG.
[Explanation of symbols]
E ... Engine 1 ... Oil tank 1A, 1B ... Air vent hole 2 ... Air vent chamber 2A, 2B ... Connection hole 2C ... Air vent 3A, 3B ... Pipe line 26 ... Crankshaft

Claims (8)

The multi-cylinder engine is mounted so that the axial direction of the crankshaft coincides with the longitudinal direction of the hull, and the oil tank is disposed so that the longitudinal direction coincides with the axial direction of the crankshaft,
Forming a first communication port and a second communication port in at least two locations spaced apart in the front-rear direction of the oil tank;
A chamber having a third communication port and a fourth communication port at two spaced apart positions, and a fifth communication port communicating with the inside of the cylinder head of the engine at another position, a bottom surface of the chamber Provided above the oil level inside the oil tank,
In addition, the first communication port of the oil tank and the third communication port of the chamber are communicated, and the second communication port of the oil tank and the fourth communication port of the chamber are communicated. A small traveling ship characterized by The multi-cylinder engine is mounted so that the axial direction of the crankshaft coincides with the longitudinal direction of the hull, and the oil tank is disposed so that the longitudinal direction coincides with the axial direction of the crankshaft,
Forming a first communication port and a second communication port in at least two locations spaced apart in the front-rear direction of the oil tank;
A chamber having a third communication port and a fourth communication port at two spaced apart positions and a fifth communication port communicating with at least one outside air at another position is provided inside the cylinder head of the engine. As a separate space, the bottom of the chamber is provided higher than the oil level inside the oil tank,
In addition, the first communication port of the oil tank and the third communication port of the chamber are communicated, and the second communication port of the oil tank and the fourth communication port of the chamber are communicated. A small traveling ship characterized by The small traveling ship according to claim 1 or 2, wherein the third communication port and the fourth communication port are provided at a distance from each other in height. The small traveling ship according to any one of claims 1 to 3, wherein a majority of the oil tank is disposed below a crank chamber of an engine. Most of the oil tank is arranged to be located below the crankcase of the engine, according to claim 1 to 3 in which the oil tank is characterized in that it is a separate independent space partitioned from the crank chamber The small traveling ship as described in any one of the items . The small traveling ship according to any one of claims 1 to 5 , wherein a fifth communication port of the chamber is connected to a base end of a breather pipe. The small traveling ship according to claim 6, wherein a tip of the breather pipe is connected to a separator that separates oil and air. The lower end of at least one of the fifth communication port of the chamber, the first communication port of the oil tank, and the second communication port protrudes inward from the wall surface around the communication port. The small traveling ship according to claim 1 or 2 .

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